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40 GROUNDWATER ANALYTICAL RESULTS Groundwater laboratory analytical results are summarized in Table 1 In the First Quarter 2004, approximately 6-inches of free floating product was observed on the water surface in groundwater monitoring well MW-3, and no groundwater sample was collected due to the presence of free ' product The highest TPHg concentration was detected in MW-1 at 29,000 micrograms per liter (ug/1) Benzene was detected in only one well, MW-7 at 0 61 ug/l The highest MTBE concentration ' was detected in MW-5 at 26 ug/l MTBE was also present in wells MW-1, MW-2 and MW-4 at concentrations that range fro4 l to 17 ug/l Other FOCs were not detected above the laboratory reporting limits in samples collected from the groundwater monitoring wells Well AS-1, located ' within the source area and screened from 40 to 45 feet below ground surface (bgs) (deeper than the monitoring wells), was sampled for the sixth time since the startup of remedial activities The groundwater sample collected from AS-1 did not contain concentrations of TPHg, BTEX, or FOCs above the laboratory reporting limits (Table 1) Copies of the laboratory analytical reports and chain- of-custody documents for the groundwater samples wells are included in Appendix C ' A decreasingcontaminant trend in groundwater has been observed since the start f r g o emediation in ' the Third Quarter 2002 (September 2002) through the Fourth Quarter 2003 (January 2004) First Quarter 2004 groundwater containmant concentrations were similar to the groundwater analytical data from the previous quarter Pursuant to the request of the RWQCB, groundwater samples from wells MW-5, MW-51), MW-6, ' and MW-9 were collected and analyzed for various meals for five consecutive quarters The analytical data did not demonstrate any trends (e g, increase in concentration) in the of dissolved metal concentrations (Table 2) However, in July 2003 iron and aluminum were detected at ' concentrations an order of magnitude higher than concentrations detected from any other sample event in wells MW-5, MW-6 and MW-9 An anomalous zinc detection was present in well MW-5, ill ' January 2004 at an order of magnitude greater than any other zinc detection, at 34 milligrams per liter (mg/1) Copies of the laboratory analytical reports and chain-of-custody documents for tine groundwater samples collected from the groundwater monitoring wells are included in Appendix C 1 The water samples collected from domestic wells DW-2R and DW-3 did not contain detectable concentrations of TPHg, BTEX or FOCs DW-1, sampled monthly, did not contain detectable concentrations of TPHg, BTEX, oxygenates, 1,2-DCA, or EDB in November or December 2003 or lanuary 2004 Copies of the laboratory analytical reports and chain-of-custody documents for the ' water samples collected from the domestic wells are included in Appendix C Proiect No 58643-06-01 -8- FLbruary 18 2004